The New York Times, in As New Services Track Habits, the E-Books Are Reading You , describes how book subscription services can provide very deep metrics about how readers interact with books. As product documentation has moved online, technical writers get some information about what is being used by customers, but this sort of insight would be fascinating, if not disheartening at times.

I'm an Oyster subscriber, by the way, and I'm really pleased with the service despite the breadcrumbs I'm apparently leaving behind.